The present invention relates to a moisture-absorbing device being in the form of a tube, which in its longitudinal direction is divided into an upper chamber containing a moisture-absorbing agent and a lower chamber containing a liquid-collecting means and communicating with the upper chamber via a liquid-permeable means.
WO 93/14996 discloses a first prior-art moisture-absorbing device of this kind, which is adapted to absorb moisture in a container whose walls have wall-stiffening folds forming vertical grooves on the inside of the walls, and which, to this end, is arranged in such a groove. In this prior-art device, the tube is made of a fine-meshed steel wire netting. The upper chamber contains a moisture-absorbing agent in the form of flakes of calcium chloride, and the lower chamber contains a liquid-collecting means in the form of liquid-absorbing particles of an agent that is marketed under the trade-name Skamol. In this device, the liquid-permeable means between the upper and the lower chamber consists of a partition in the form of a steel wire netting. The calcium-chloride flakes and the Skamol particles are larger than the meshes in the steel wire netting forming the tube and they are therefore retained in the tube, while air may enter. These flakes and particles are also larger than the meshes of the steel wire netting forming the partition and they are therefore retained in the respective chambers, while liquid may pass through the partition.
The above prior-art device suffers from certain drawbacks. If the device is handled carelessly, for instance during transport, the steel wire netting forming the tube can easily be damaged, thus allowing flakes and particles to escape from the tube. When the liquid-absorbing agent is saturated with liquid, liquid can escape from the device and cause damage to the goods kept in the container.
WO 95/26914 discloses a second prior-art moisture-absorbing device, which is of the kind stated by way of introduction and, in the same way as the above-mentioned first prior-art device, is adapted to be arranged in a vertical groove in a container, the tube being made of corrugated fiberboard coated with plastic and having at least one opening on a level with the upper chamber. A netting element, which has at least one fine-meshed netting portion, is attached to the inside of the tube, in such a manner that the netting portion is positioned in front of said opening. The liquid-permeable means between the upper and the lower chamber comprises a non-return valve means, which is liquid permeable only in the direction away from the upper chamber to the lower chamber. The liquid-collecting means consists of a plastic bag, which is connected to the liquid-permeable means.
In the second prior-art device, the above drawbacks of the first known device have been obviated. However, the second prior-art device is somewhat complicated to manufacture as a plurality of gluing operations are needed and several operational steps are required for mounting the plastic bag.
In a third prior-art moisture-absorbing device, which is disclosed in WO 97/43193 and which is of the kind mentioned by way of introduction, the tube is an extruded plastic tube, which in its longitudinal direction is divided into an upper chamber containing a moisture-absorbing agent, and a liquid-collecting lower chamber communicating with the upper chamber via a grating element. The tube has an opening on a level with the upper chamber. A netting element, which has a fine-meshed netting portion, is attached to the tube, so that the netting portion is positioned in front of the opening.
The tube is closed at its lower end to permit the collection of liquid in the lower chamber.
In the third prior-art device, the above drawbacks of the first and second prior-art devices are eliminated. However, the third prior-art device has, as well as the other two prior-art devices, the important inconvenience of being relatively bulky and thus taking up a great deal of space during storage and transport.
An object of the present invention is to provide a moisture-absorbing device, in which also the last-mentioned drawback has been eliminated and which moreover is very simple and cheap to manufacture.
According to the present invention, this object is achieved by means of a moisture-absorbing device in the form of a tube, which in its longitudinal direction is divided into an upper chamber containing a moisture-absorbing agent and a lower chamber containing a liquid-collecting means and communicating with the upper chamber via a liquid-permeable means, the tube having at least one opening on a level with the upper chamber, and a netting element, which has at least one netting portion, being attached to the tube, in such a manner that the netting portion is positioned in front of said opening, said device being characterized in that the tube consists of a plastic tube which is closed at its lower end and made of flexible plastic sheet, the upper portion of the plastic tube forming the upper chamber and its lower portion forming the lower chamber as well as the liquid-collecting means.
In a preferred embodiment, the moisture-absorbing agent is included in a filtering tube, which is made of an air- as well as liquid-permeable filtering material and which is arranged in the upper chamber substantially in front of said opening. The filtering tube is preferably closed at its lower end, the filtering material at this end forming the liquid-permeable means. Suitably, the filtering tube has a smaller cross-sectional area than the plastic tube has in its upper portion.